PrintRecommendationService: Remove CloudPrintPlugin

The server side of the Cloud Print service was turned down in 2021, so
no printers can be used with this service any more.  Remove
CloudPrintPlugin from PrintRecommendationService so that this print
service is no longer recommended even if printers locally respond to the
_privet._tcp mDNS query.

Bug: 321936819
Test: build
Change-Id: If11aca3911bda055df823fcc5287e24110bb5c23